1 #!/usr/sbin/dtrace -Zs 2 /* 3 * js_objgc.d - trace JavaScript Object GC using DTrace. 4 * Written for the JavaScript DTrace provider. 5 * 6 * $Id: js_objgc.d,v 1.1.1.1 2015/09/30 22:01:09 christos Exp $ 7 * 8 * This traces JavaScript activity from all running browers on the system 9 * which support the JavaScript DTrace provider. 10 * 11 * USAGE: js_objgc.d # hit Ctrl-C to end 12 * 13 * FIELDS: 14 * FILE Filename that contained the function 15 * CLASS Class to which this new object belongs 16 * TOTAL Object entropy (positive == uncollected) 17 * 18 * This script provides information on which objects are not being garbage 19 * collected, an issue which causes the browser to steadily leak memory. 20 * We trace object creation (+1) and destruction (-1), and provide a 21 * summary each second of the running tally of the object class and 22 * originating filename. If over the period of several minutes an object 23 * type is still steadily increasing, then that would be of interest. 24 * Be patient, depending on the rate of object creation it can take over 25 * ten minutes for garbage collect to kick in. 26 * 27 * NOTES: 28 * - it is possible that you will see negative entropy. That happens 29 * when you begin tracing after some objects have already been created, 30 * and then trace their destruction. 31 * - there are other Things that GC handles, other than Objects; extra 32 * probes can be added to trace them, should the need arise. 33 * 34 * COPYRIGHT: Copyright (c) 2007 Brendan Gregg. 35 * 36 * CDDL HEADER START 37 * 38 * The contents of this file are subject to the terms of the 39 * Common Development and Distribution License, Version 1.0 only 40 * (the "License"). You may not use this file except in compliance 41 * with the License. 42 * 43 * You can obtain a copy of the license at Docs/cddl1.txt 44 * or http://www.opensolaris.org/os/licensing. 45 * See the License for the specific language governing permissions 46 * and limitations under the License. 47 * 48 * CDDL HEADER END 49 * 50 * 09-Sep-2007 Brendan Gregg Created this. 51 */ 52 53 /* if you get dynvardrops, increase this, */ 54 #pragma D option dynvarsize=32m 55 #pragma D option quiet 56 57 dtrace:::BEGIN 58 { 59 printf("Tracing... Hit Ctrl-C to end.\n"); 60 } 61 62 javascript*:::object-create 63 /arg2/ 64 { 65 this->file = basename(copyinstr(arg0)); 66 @objs[this->file, copyinstr(arg1)] = sum(1); 67 filename[arg2] = this->file; 68 } 69 70 javascript*:::object-finalize 71 /filename[arg2] == NULL/ 72 { 73 @objs["<missed>", copyinstr(arg1)] = sum(-1); 74 } 75 76 javascript*:::object-finalize 77 /filename[arg2] != NULL/ 78 { 79 @objs[filename[arg2], copyinstr(arg1)] = sum(-1); 80 filename[arg2] = 0; 81 } 82 83 profile:::tick-1sec, 84 dtrace:::END 85 { 86 printf("\n %-24s %8s %-20s %23Y\n", "FILE", "TOTAL", "CLASS", 87 walltimestamp); 88 printa(" %-24.24s %@8d %s\n", @objs); 89 } 90